This invention is generally directed to toner and developer compositions, and more specifically the present invention is directed to toner compositions, including magnetic, single component, and colored toner compositions comprised of a new third form of carbon. In one embodiment of the present invention, the toner compositions are comprised of resin particles, and pigment particles comprised of any one of the fullerenes, such as buckminsterfullerene, giant fullerenes or mixtures thereof. There are also provided in accordance with the present invention toner compositions comprised of resin particles, pigment particles comprised of buckminsterfullerene, any one of the fullerenes, giant fullerenes or mixtures thereof, and charge enhancing additives. Furthermore, there is provided in accordance with the present invention toner compositions wherein the buckminsterfullerene or fullerenes can be present as external or internal additives. In addition, the present invention is directed to developer compositions comprised of the aforementioned toners and carrier particles. Furthermore, in another embodiment of the present invention there are provided single component toner compositions comprised of resin particles, magnetic components such as magnetites, and pigment particles comprised of buckminsterfullerene, any one of the fullerenes, giant fullerenes, high molecular weigh fullerenes, or mixtures thereof. The toner and developer compositions of the present invention are useful in electrostatographic imaging systems, especially xerographic imaging and printing processes.
Molecular fullerenes have been described as entirely closed, hollow spheroidal shells of carbon atoms containing 32 to 1,000 or more carbon atoms in each sphere, reference Smalley, R. E. "Supersonic Carbon Cluster Beams in Atomic and Molecular Clusters", Bernstein, E. R., Ed.; Physical and Theoretical Chemistry, Vol. 68, Elsevier Science: New York, 1990; pages 1 to 68, the disclosure of which is totally incorporated herein by reference. The prototypical fullerene, C.sub.60, has been referred to as buckminsterfullerene and has the molecular geometry of a truncated icosahedron, thus the C.sub.60 molecules resemble a molecular sized soccer ball, reference Time Magazine, May 6, 1991, page 66, and Science, vol. 252, Apr. 12, 1991, page 646, the disclosure of which is totally incorporated herein by reference. Molecules of C.sub.60 as well as of C.sub.70 and of other fullerenes have also been referred to as buckyballs. Buckminsterfullerene usually consists of C.sub.60 molecules contaminated with small amounts of C.sub.70 and possibly C.sub.84 molecules or even smaller amounts of higher molecular weight fullerene molecules. The preparation of buckminsterfullerene and of other fullerenes from the contact arc vaporization of graphite and a number of the buckminsterfullerene characteristics such as solubility, crystallinity, color and the like, have been described in Kratschmer, W., Lamb, L. D., Fostiropoulos, K., Huffman, D. R., Nature, 1990, Vol. 347, pages 354 to 358 and in Chemical and Engineering News, Oct. 29, 1990, pages 22 to 25 , the disclosures of which are totally incorporated herein by reference. The fullerenes are available from Texas Fullerenes Corporation, 2415 Shakespeare Suite 5, Houston, Tex. 77030-1038, Materials & Electrochemical Research (MER) Corporation, 7960 South Kolb Road, Tucson, Ariz. 85706, and Research Materials, Inc., 1667 Cole Boulevard, Golden, Colo. 80401, and are believed to be comprised of mainly C.sub.60 and smaller amounts of C.sub.70 and C.sub.84 carbon molecules, and possible small amounts of other higher molecular weight fullerenes. It is believed that these new forms of carbon possess a number of advantages for toners, including, for example, their solubility in organic solvents. The other known carbon forms, diamond and graphite and derivatives thereof, are not considered to be soluble in such solvents. Solubility in organic solvents enables improved processing and the economical preparation of toner compositions wherein the optical density is considered low since the fullerenes are of different colors and are of substantially lower optical density than ordinary carbon black, thereby enabling their use in colored toners with, for example, cyan, magenta, yellow, red, green, and brown toners. Moreover, the surface conductivity characteristics of derivatized fullerenes can provide for conductive toners. Also, the fullerenes may be selected as toner charge enhancing additives, especially for colored toners. Further, the fullerenes may be deposited on known surface flow additives, such as colloidal silicas like the AEROSILS.RTM., such as AEROSIL R972.RTM., and the resulting product selected as a charge additive for toner compositions.
Developer and toner compositions with carbon black pigments, such as REGAL 330.RTM. carbon black, are known. Also, toners and developers with certain charge enhancing additives and surface additives are known. Representative patents disclosing the aforementioned toners and developers include U.S. Pat. Nos. 3,590,000; 4,298,672; 4,560,635; 4,937,166 and 4,935,326, the disclosures of which are totally incorporated herein by reference. Also known are toners and developers with colored pigments, such as cyan, yellow, magenta, and mixtures thereof, and toners with additives such as waxes, like polypropylene, or polyethylene. Additionally, toners with surface additives such as silicas, metal salts of fatty acids, and the like are known.
More specifically, developer and toner compositions with certain waxes therein are known. For example, there are disclosed in U.K. Patent Publication 1,442,835 toner compositions containing resin particles and polyalkylene compounds, such as polyethylene and polypropylene of a molecular weight of from about 1,500 to 6,000, reference page 3, lines 97 to 119, which compositions prevent toner offsetting in electrostatic imaging processes. Additionally, the '835 publication discloses the addition of paraffin waxes together with, or without a metal salt of a fatty acid, reference page 2, lines 55 to 58. In addition, many patents disclose the use of metal salts of fatty acids for incorporation into toner compositions, such as U.S. Pat. No. 3,655,374. Also, it is known that the aforementioned toner compositions with metal salts of fatty acids can be selected for electrostatic imaging methods wherein blade cleaning of the photoreceptor is accomplished, reference Palmeriti et al. U.S. Pat. No. 3,635,704, the disclosure of which is totally incorporated herein by reference. Additionally, there are illustrated in U.S. Pat. No. 3,983,045 three component developer compositions comprising toner particles, a friction reducing material, and a finely divided nonsmearable abrasive material, reference column 4, beginning at line 31. Examples of friction reducing materials include saturated or unsaturated, substituted or unsubstituted, fatty acids preferably of from 8 to 35 carbon atoms, or metal salts of such fatty acids; fatty alcohols corresponding to said acids; mono and polyhydric alcohol esters of said acids and corresponding amides; polyethylene glycols and methoxy-polyethylene glycols; terephthalic acids; and the like, reference column 7, lines 13 to 43.
Toner and developer compositions containing charge enhancing additives, including additives which impart a positive charge to the toner resin, are well known. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of certain quaternary ammonium salts as charge control agents for electrostatic toner compositions. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. Further, there are illustrated in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer and toner compositions having incorporated therein as charge enhancing additives organic sulfate and sulfonate compositions; and in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions containing resin particles and pigment particles, and as a charge enhancing additive alkyl pyridinium compounds, inclusive of cetyl pyridinium chloride.
Other prior art disclosing positively charged toner compositions with charge enhancing additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014 and 4,394,430. Toners with aluminum complex charge additives are illustrated in U.S. Pat. No. 4,845,003. The disclosure of each of the United States patents is totally incorporated herein by reference.